[Tralien]

hello,

i am a new user in the k20a.org forum. i am from germany driving a civic type-r. last week i got my k-pro and started with the standard dyno tuned map. dyno run says 180 whp, thats 20 more than a euro civic originally has.
here is the output curve and a small vid

Video

i am quite satisfied with the result and the power, but i still have one problem. my civic should run 235 km/h, but i is like it runs against a wall at ca. 230. shouldnt i easily achieve the manufactor information for the topspeed of 235 km/h with 20 ps over stock?

please give me some hints

 

[iwilson]

First question I'd ask is what could it do before you tuned it. Secondly as your speed increases the amount of power needed rises by the cube (once drag really comes into effect i.e. over about 100kmph). In other words to double your speed you need *eight* times the power. Or to put it another way if you have increased your power by 10% you will only go 3% faster. So an increase of 20hp is not going to make much difference in the scheme of things. Manufacturer's claims should be taken with a pinch of salt and the speedo is probably a few percent out (nearly all manufacturer's make the speedo over read) so I doubt you're even getting to 230kmph...

 

[lifendet]

max speed also depends on gear ratio especially ur final drive ratio...so its not only ur whp#

 

[iwilson]

max speed also depends on gear ratio especially ur final drive ratio...so its not only ur whp#

Kind of. As long as the engine is geared so it can approx. reach the peak power point that's good enough. This is because it takes a large change in power to effect a relatively small change in top speed. So if the engine is not able to reach max power in top gear and is say 10 - 20hp away from peak power it won't acutally make much of a difference to the top speed. Gearing is more useful as a tool to increase acceleration, since the gear box acts as a torque multiplier.

 

[Tralien]

as you can see the dyno run was made in 6th gear. the 180 whp / 220 engine ps are measured at topspeed, 257 km/h and 8000 rpm.

when the car was stock, it did the same topspeed, the 20 whp gain didnt raise the topspeed. when you shift into 6th gear at 210 km/h nearly all acceleration is blown away although the power is present.

my final drive ratio is still untouched and i shoud be able to achieve the manufactors topspeed with a stock gearbox and enough power, shouldnt i?

 

[jon v]

So you are not hitting a governor or anything you just don't have the power to go any faster, or so it seems?

 

[Tralien]

yes, it seems that i dont have enough power, but i do have the power. almost all ctr drivers here in germany reach 245 kmph with nearly stock civics.